You can set the CPU affinity through a command line parameter to the start.exe program. do start.exe /? to see the options, then google if you need more documentation. I used this and created a batch file that puts all the processes to belownormal priority and all assigned to a single CPU core, so it doesn't slow down my system. They still pretty much use 100% of that one core, but I have a quad core so no big deal.

On any system that dynamically adjusts core voltage with load, this -is- a big deal. Loading up one core will still bump the core voltage way up. It will cause a significant waste of power on an otherwise idle system.

On any system that dynamically adjusts core voltage with load, this -is- a big deal. Loading up one core will still bump the core voltage way up. It will cause a significant waste of power on an otherwise idle system.

I hope they fix this nonsense soon.

You are absolutely right. Those clock cycled are wasted! What sucks is that this issue has been known for a long time yet there is no fix yet. Someone clearly doesn't give a shit at AMD.

I am using ATI HD 5750, with an E8400 Core™2 Duo processor under windows 7 and I do not have this issue with the latest drivers. My CPU usage is close to 0.

There's your answer. The problem is NOT the drivers it is the Stream SDK which just so happens to be included in the Catalyst packages these days. The 5 series cards are compatible with ATI Stream SDK 2.1 which does not utilize the cpu. SDK 2.2 started utilizing the cpu to full capacity. The 6 series cards are not compatible with SDK 2.1. For those of you who have the 6 series cards, your stuck with it, at least on windows anyway.

All who want to avoid 10-100% CPU usage, also windows not mining with more than 4 GPU's......all problem related to windows->opencl->mining have to send/write to the below forum, coz it deals with opencl.

OpenCL is the root cause of all the problems, from windows not supporting more than 4 GPU's, 100% usage.... Instead of NO ONE asking or writing in AMD DEVELOPER forum, AMD DEVELOPER WILL NEVER know the problem.Also, if you write to AMD, they won't care, as it MUST be addressed by developers not product division.

So, better don't mass mail, but REGISTER in the developer forum & ask them what features you want, both in Windows & Linux. Only developer forum can solve all the Windows/Linux->OpenCL issues. No others can solve that.

In this thread i accused mining software developers for blocking/limiting 4 GPU's only in Windows.I was wrong. I came to learn that, its not Windows or mining programs, but its due to limitation in OpenCL.The misunderstood is due to the reason, no one had time to explain why in Windows with more than 4 GPU's can't mine.All i got was Windows won't mine more than 4 GPU's, if you want to go for more than 4 GPU's switch to Linux.This is the only thing i heard. I also may not be knowledgeable/intelligent enough to read some one's post/thread which clearly said its due to OpenCL.

Actually the post of iamzill which divided the problem & cleared me to question where is the problem.

Quote

There's some misunderstanding here.

In order to you to mine on a GPU, the following statements must all be true:1. Your GPU must be detected by your OS2. Your GPU must be detected by the ATI openCL driver3. Your GPU must be detected by your miner

The current problem is that ATI's Windows openCL drivers does not work with more than 4 cards. The onus is on you to prove it otherwise. I'm sure many developers would've love to overcome this limitation, but none have succeed so far.

Your screenshot shows that Windows can detect 7 GPUs for the purposes of displaying pictures, but without the help of proprietary drivers Windows cannot do any computation with them. The 4 GPU/OS limitation lies with the proprietary drivers, and not Windows or the miner developers.

From his post, i got doubt that it may be OpenCL & searched sites & found out, that it is OpenCL.

Before i try to post my findings & apologies, one miner got angry & posted & many complained to moderator, that made him to lock the thread.

I wanted to post this next day itself, but due to many problem i faced, i can't able to post.

All the miners who wrote & writing mining programs apologize me for accusing mining writers in general with out knowing the fact that it is not miners fault, but it is OpenCL & particularly AMD not developing.

I apologize to all miners that i scolded you unnecessarily without knowing the fact.Forgive me for my no knowledge & no intelligent.

As said above, instead of keep on saying i am getting 10-100% or even 1000% CPU usage, better post to DEVELOPERS forum of AMD.

I am using ATI HD 5750, with an E8400 Core™2 Duo processor under windows 7 and I do not have this issue with the latest drivers. My CPU usage is close to 0.

There's your answer. The problem is NOT the drivers it is the Stream SDK which just so happens to be included in the Catalyst packages these days. The 5 series cards are compatible with ATI Stream SDK 2.1 which does not utilize the cpu. SDK 2.2 started utilizing the cpu to full capacity. The 6 series cards are not compatible with SDK 2.1. For those of you who have the 6 series cards, your stuck with it, at least on windows anyway.

I still had no CPU usage on stream SDK 2.4, but lower hashrate so I downgraded